1. Field of the Invention
Embodiments of the invention described herein pertain to the field of well fluid wetted assemblies. More particularly, but not by way of limitation, one or more embodiments of the invention enable abrasion resistance in well fluid wetted assemblies.
2. Description of the Related Art
Fluids containing hydrocarbons, such as oil and natural gas, are often located in underground formations. In such situations, the oil or gas must be pumped to the surface so that it can be collected, separated, refined and sold. Many of these underground formations also contain well born solids, such as consolidated and unconsolidated sand. The hydrocarbon laden fluids must pass through the sand on their way to the pump intake, and ultimately to the surface. When this occurs, the hydrocarbon fluids carry the sand through pump components. Such well-born solids may have severe abrasive effects on the submersible pump components and increase the heat generated during use, since abrasive wear to the pump causes inefficiency in its operation. As a result, careful attention to fluid and pressure management in submersible pump systems is needed in order to improve the production of hydrocarbon laden fluids from subsurface formations.
Currently available submersible pump systems are not appropriate for some well applications. Particularly, pump components used in oil or gas production applications should be exceptionally resistant to erosive wear. When a pump is used in an oil or gas well, equipment failure is especially costly as this can impede well production and replacing parts is undesirable since the equipment is deep in the ground. Care must be taken in cooling the pump equipment and avoiding the damage caused by abrasive materials in the produced well fluid.
In the case of an electric submersible pump (ESP), a failure of the pump or any support components in the pump assembly can be catastrophic as it means a delay in well production and having to remove the pump from the well for repairs. Downhole applications in particular require that ESP pumps be able to survive constant exposure to abrasive materials in the well fluid as well as the heat generated when the pump is in operation. A submersible pump system with improved thrust handling and radial support capabilities, such as an improved ability to withstand abrasion and heat, would be an advantage in all types of submersible and non-submersible assemblies.
Currently available pump assemblies contain bearing surfaces. FIGS. 1A-1C illustrate an example of a “Mixed Flow” thrust bearing surface of the prior art. FIG. 1A is a top view of a conventional stationary member. FIG. 1B is a cross section along line 1B-1B of a conventional stationary member. FIG. 1C is a perspective view of a conventional rotating member. In conventional assemblies, the rotating member of FIG. 1C is keyed to the shaft of a submersible pump and rotates with the shaft as fluid is pumped to the surface of a well. The stationary member of FIGS. 1A, 1B is attached to the wall of the diffuser of the submersible pump and does not rotate. Conventional designs are not well suited to withstand excessive abrasion in pumping systems or to keep the bearing surfaces cool. These shortcomings decrease the longevity of the pump components.
Therefore, there is a need for better abrasion resistance in well fluid wetted assemblies to more readily withstand the effects of well-born solids and improve cooling characteristics, thereby improving the lifespan of the pump and pump components in submersible pump applications.